1. Field of the Invention
The present invention relates to a technique for recording information on an optical disk by irradiating a laser beam.
2. Description of the Related Art
An optical disk such as CD, DVD, or the like is used as a recording medium of data such as computer data, audio/visual data, or the like.
The data recording on the optical disk is performed by irradiating a laser beam converged by a lens on a recording surface of the optical disk and forming marks and spaces. A laser light emission waveform according to a length of recording mark is used to record the mark. The laser light emission waveform is called write strategy. The write strategy is constructed by: pulse timing which specifies a rising edge, a falling edge, and a recording pulse width of the laser beam; and recording power which specifies laser power.
As a deciding method of the pulse timing at an arbitrary recording linear velocity in the write strategy, there is a deciding method disclosed in JP-A -2004-86999. The pulse timing at an arbitrary recording linear velocity is obtained from the pulse timing at two recording linear velocities by linear interpolation. As a deciding method of the pulse timing in the case where the linear interpolation is not used, there is a method of adjusting parameters so that recording quality can be assured at recording linear velocities at both ends of each zone.
As a setting method of the recording power at an arbitrary recording linear velocity in the write strategy, there is a deciding method disclosed in JP-A -5-225570. According to such a method, the optimum recording power at two or more recording linear velocities is obtained and the recording power is changed by the linear interpolation or the like at a recording velocity between the two recording linear velocities.